Pipes used for the conveyance of domestic sewage and industrial waste, except those of small diameter, are usually formed of concrete as this is the only economical material available. The use of concrete pipe presents serious difficulties in the transporting of sewage and wastes because the concrete is sometimes attacked by the action of the liquids and gases present in the material conveyed. Sewage gases have been found particularly destructive of the concrete in many localities and in view of this various attempts have been made to provide a lining for the pipe which will not be attacked by the material carried or the gases given off therefrom.
Linings have been applied both as a continuous coating and in the form of a multiplicity of liner plates. The various surface coatings which have been tried present difficulties in the securing of a tight bond to the wall of the pipe and in the securing of an impervious and abrasion-resistant surface. The results of these difficulties are that the surface failed to prevent the infiltration of destructive liquids and gases to the concrete, and the defective bond at times permitted scaling off and cracking of the lining.
In view of the difficulties and disadvantages of the various types of linings for concrete pipes, a new and improved concrete pipe with liner is desirable.